1. Field of the Invention
This invention relates to a method of manufacturing a semiconductor device.
2. Brief Description of Related Art
In the manner which will be described more in detail, a first method of manufacturing a semiconductor device comprises steps of preparing a semiconductor substrate to have a principal surface; forming a first insulator layer on the principal surface having a first recessed surface which defines a first hole exposing a first predetermined area of the principal surface; forming a second insulator layer on the first predetermined area of the principal surface; forming a polycrystal silicon layer on the first and the second insulator layers to have phosphorus particles; forming a titanium nitride layer on the first polycrystal silicon layer by using a sputtering method which uses titanium; and forming a titanium silicide layer on the titanium nitride layer by using a sputtering method which uses titanium silicide alloy.
In the method of manufacturing the semiconductor device, inasmuch as the titanium silicide layer is corroded when the first contact hole is formed in the second insulator layer formed on the titanium silicide layer by using etching, it is difficult to reliably manufacture the semiconductor device. Also, in the method of manufacturing the semiconductor device, it is required to use both of titanium and titanium silicide alloy.
In the manner which will be described more in detail, a second method of manufacturing a semiconductor device comprises steps of preparing a semiconductor substrate having a principal surface; forming a first insulator layer on a predetermined area of the principal surface having a first upper insulator surface; forming an impurity diffusion layer in a surface part of the semiconductor substrate having impurities in the impurity diffusion layer; forming a second insulator layer on the first upper insulator surface and an impurity diffusion surface in the impurity diffusion layer; forming, in the first and the second insulator layers, a recessed surface which defines a contact hole exposing a predetermined area of the impurity diffusion surface; forming a titanium silicide layer on the predetermined area of the impurity diffusion surface and the recessed surface by using a sputtering method which uses titanium silicide alloy; and forming a titanium nitride layer on the titanium silicide layer by using a sputtering method which uses titanium.
In the method of manufacturing the semiconductor device, inasmuch as the titanium nitride layer is easily oxidized, it is difficult to reliably manufacture the semiconductor device. Also, in the method of manufacturing the semiconductor device, it is required to use both titanium and titanium silicide alloy.